1. Field of the Invention
The present invention relates to an optical information recording medium, which has a structure of recording information by using the packet writing recording format for a CD-R disc and a structure capable to read out recorded information from the top through the last recorded packet by a CD-ROM drive even when a recordable area still remains in such a recording medium.
2. Description of the Related Art
A recordable type of information recording medium such as a CD-R disc became popular recently that a recorded disc can be treated equally as a CD-ROM disc and that the recorded information can not be interpolated.
There are four types of recording format for the CD-R disc such as DAO (Disc At Once), SAO (Session At Once), TAO (Track At Once) and PW (Packet Writing).
FIG. 8 is a diagram for explaining the recording format of DAO. This format is the basic recording format for a CD-R disc and it has almost the same structure of the recording format for a read-only CD disc such as a CD-DA disc and a CD-ROM disc.
As shown in FIG. 8, a CD-R disc is composed of an area A, typical of a CD-R disc, and an area B, common to a read-only CD disc. The area A consists of a {circle around (1)} PCA (Power Calibration Area) area and a {circle around (2)} PMA (Program Memory Area) area. The {circle around (1)} PCA area is an area for determining an optimum recording laser power for a CD-R disc, and the {circle around (2)} PMA area is a data recording area for recording a temporal lead-in information before writing the lead-in information in a {circle around (3)} lead-in area actually. As the recording formats of DAO and SAO write information in the {circle around (3)} lead-in area and a {circle around (5)} lead-out area simultaneously with a {circle around (4)} program area, it is not necessary to write the temporal lead-in information in the {circle around (2)} PMA area. As the area A does not directly impact the following, the detailed description for the area A is omitted.
The area B consists of the {circle around (3)} lead-in area, the {circle around (4)} program area and the {circle around (5)} lead-out area, and is called a xe2x80x9csessionxe2x80x9d. The {circle around (3)} lead-in area is an area for recording a starting time of recording information in the {circle around (4)} program area and the {circle around (5)} lead-out area and for recording a type of data to be recorded in the {circle around (4)} program area. The {circle around (4)} program area is composed of a plurality of tracks and each track is recorded with an user information to be recorded. The {circle around (5)} lead-out area is recorded with an information indicating the end of the {circle around (4)} program area.
The area B of the DAO format has the same structure of the recording area of a read-only CD disc as described above to enable the CD-R disc recorded in the DAO format being lead-out by a CD-ROM disc drive.
FIG. 9 is a diagram for explaining the SAO format. The SAO format is a format developed from the DAO format and is for recording information repeatedly in a session unit of the {circle around (3)} lead-in area, the {circle around (4)} program area and the {circle around (5)} lead-out area. In the case of FIG. 9, it shows two sessions indicated as an area Bxe2x80x2. The first session consists of {circle around (3)} lead-in area, {circle around (4)} program area and {circle around (5)} lead-out area and the second session consists of {circle around (3)}xe2x80x2 lead-in area, {circle around (4)}xe2x80x2 program area and {circle around (5)}xe2x80x2 lead-out area. In the SAO format, as the recording operates in the session unit, a recorded CD-R disc can be used for reading out information by a CD-ROM disc drive or a CD-R disc drive for multi-section application.
The TAO format is developed from the SAO format to reduce an area unavailable for user data in the SAO format by dividing each session area in a track unit and to make such an area recordable.
More specifically, the lead-out area and the lead-in area are necessary in one session for recording information in the session unit by the SAO format, and further, in the case of FIG. 9, such the format requires 90 seconds for recording in the {circle around (5)} lead-out area and 60 seconds for recording in the {circle around (3)}xe2x80x2 lead-in area. The TAO format is to reduce these areas unavailable for user data recording. Consequently, there is a benefit of recording more user information in the {circle around (4)} program area. Generally, the TAO format has one session and divides one session into a plurality of tracks and records information in the track unit.
FIG. 10 is a diagram for explaining recording format of the TAO format. In FIG. 10, the TAO format has one session and the {circle around (4)} program area is composed of three tracks. Each track is {circle around (4)}-1 track #1, {circle around (4)}-2 track #2, and {circle around (4)}-1 track #3 from the top. The recording is carried out in the order of track #1, #2, and #3 in the track unit.
After the recording in the {circle around (4)}-3 track #3 is completed, the lead-in information is recorded in the {circle around (3)} lead-in area and the lead-out information in the {circle around (5)} lead-out area respectively, which is called finalization. As a result of this finalization, a CD-R disc recorded by the TAO format can be used for reading out information by a CD-ROM disc drive.
FIG. 11 is a diagram for explaining recording format of the PW format. The PW format is a recording format subdivides the track unit into a packet unit. As this recording format records information into a smaller packet unit, many files can be recorded in a CD-R disc as if such files are recorded in a floppy disc. The {circle around (4)} program area may have a plurality of tracks which is more than two.
In the case of FIG. 11, the {circle around (4)} program area consists of the {circle around (4)}-1 track #1 and this track #1 consists of three packets a {circle around (4)}-1-1 packet #1, a {circle around (4)}-1-2 packet #2, and a {circle around (4)}-1-3 packet #3.
FIG. 12 is a diagram for explaining a packet recording format for the PW format. In FIG. 12, the PW format has a structure of 32 user data blocks having  predetermined blocks preceding and succeeding the user data blocks such that a link block (1 block) and a run-in block (4 blocks) precedes the user data blocks, and a run-out block (2 blocks) succeeds the user data blocks. Each block is corresponding to 2 k-byte of a sector configuration of CD-ROM disc (thus, one block corresponds to a data amount of one sector).
The head link block (1 block) is for connecting with a run-out block in a preceding packet seamlessly and the subsequent run-in blocks (4 blocks) are run up portions for synchronizing with a sector of CD-ROM disc. The run-out blocks (2 blocks) are a protection area of the user data blocks for connecting with a subsequent link block seamlessly.
As shown in FIG. 11, the PW format records information in three packets (packet #1 through packet #3) and the lead-in information and lead-out information are recorded in the {circle around (3)} lead-in area and the {circle around (5)} lead-out area respectively by the finalization. The CD-R disc recorded and finalized by the PW format can be read by a CD-ROM disc drive.
FIG. 13 is a diagram for explaining an unfinished recording status of xe2x80x9cbefore the finalizationxe2x80x9d in the PW format shown in FIG. 11 such that two packets are recorded but the last packet is not yet recorded before the finalization. In FIG. 13, before the finalization, an area and a packet shown by a dotted line (i.e. the {circle around (3)} lead-in area, the {circle around (4)}-1-3 packet #3 and the {circle around (5)} lead-out area) indicate that information is not recorded, and the packets shown by a solid line (i.e. the {circle around (4)}-1-1 packet #1 and the {circle around (4)}-1-2 packet #2) indicate that the information is recorded in these packets. In this state of a CD-R disc recorded by the PW format, the disc can not be read by a CD-ROM disc drive unless the disc is finalized such that lead-in and lead-out information is recorded in the {circle around (3)} lead-in area and the {circle around (5)} lead-out area respectively.
A CD-R disc, which can be read by a conventional CD-ROM disc drive, is required to have a structure of the area B as shown in FIG. 8. However, the area A typical for the CD-R disc can not be recognized by the CD-ROM disc drive.
FIG. 14 is a diagram for explaining problems of a CD-R disc, which is recorded in the PW format shown in FIG. 13 at the status of xe2x80x9cbefore the finalizationxe2x80x9d, wherein the CD-R disc can not be read by a CD-ROM disc drive.
The problem 1 shown in FIG. 14 is that the CD-ROM disc drive can not start a readout operation as it can not read the lead-in information. The CD-ROM disc drive firstly reads out summary information for the disc which is one of lead-in information such as the TOC (Table of Contents) in the {circle around (3)} lead-in area. As the lead-in information can not be read from the {circle around (3)} lead-in area of the CD-R disc at the status of xe2x80x9cbefore the finalizationxe2x80x9d as shown in FIG. 13, the TOC information can not be readout and consequently, the lead-out operation stops.
The problem 2 shown in FIG. 14 is that a servo system for the CD-ROM disc drive becomes out of control when an optical pick-up proceeds to read a not recorded packet allocated immediately after the last packet recorded. As the optical pick up tries to read an area not recorded, the CD-ROM disc drive can not carry out a tracking servo signal or a CLV (Constant Linear Velocity) signal and the servo system becomes out of control. In other words, the CD-ROM disc drive can not recognize the last packet (in the case of FIG. 13, it is the {circle around (4)}-1-2 packet #2), which is recorded, in the CD-R disc recorded in the PW format before the finalization, and the servo system becomes out of control.
Thus, a CD-R recorder can lead-out information from the CD-R disc before the finalization wherein an information is recorded in the form of packet but the CD-ROM disc drive can not read out information from the same.
In a case of reading out information from the last packet shown in FIG. 13, as for a CD-R disc drive, it has a function to obtain a tracking signal and a CLV (Constant Linear Velocity) servo signal from the CD-R disc no matter the disc area (area B) is recorded or not. In this sense, the read out operation will continue as the tracking signal and the CLV servo signal can be obtained by the ATIP (Absolute Time In Pre-groove) signal pre-recorded in a serial groove of the CD-R disc. The recording operation for the packet can be continued for the next packet after the recording signal in the ultimate packet is confirmed.
As for the CD-ROM disc drive, it can not obtain information after reading out information from the {circle around (4)}-1-2 packet #2 that whether or not a recorded packet exists in the subsequent portion. The disc drive then tries to read out information from the {circle around (4)}-1-3 packet #3 which has no recorded information, and consequently, the servo system becomes out of control. Only then the {circle around (4)}-1-3 packet #3 is to be determined as a blank recording area.
As the CD-ROM drive tries to read out information from a blank recording area, the servo system such as the tracking servo and the CLV servo operations become out of control. If the disc drive becomes out of control, a computer which controls such the disc drive may be hang-up in some cases.
Accordingly, in consideration of the above-mentioned problems of the related art, an object of the present invention is to provide an optical information recording medium having a data format of which all recorded information throughout recorded packets from the head packet to the final packet can be lead-out by a CD-ROM disc drive even though a recordable area still exists in the optical information recording medium, wherein the optical information recording medium is recorded by using the recording format of the packet writing format of a CD-R disc.
In order to achieve the above object, the present invention provides, according to an aspect thereof, an optical information recording medium including a PCA area, a PMA area, a lead-in area, a program area, and a lead-out area in sequence for recording information in conformity with the CD-R packet writing format, the optical information recording medium further including a first area having the PCA area and the PMA area, and a second area having the lead-in area, the program area and the lead-out area, wherein the program area is composed of at least one track, wherein the track is composed of at least one packet, wherein the packet is composed of at least a user data block, an address block and a dummy block, and wherein the lead-in area is pre-recorded with at least an information related to a number of the track, a starting time of the track and a starting time of a read out operation prior to any recording, the optical information recording medium is furthermore characterized in that the address block in a last packet at a present recording session is recorded with an information representing an end of recording, and that the end of recording information recorded at a previous recording session is disabled from being lead-out, and that a packet having an address block, which can read out an end of recording information, is determined to be a last packet and a next recording session starts from a packet allocated immediately after the last packet.
Other object and further features of the present invention will be apparent from the following detailed description when lead-in conjunction with the accompanying drawings.